Internal-combustion engine



c. E. LUCKE INTERNAL COMBUSTION ENGINE Filed July 25, 1921 m A l 0 June21, 1927.

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Patented June 21, 1927.

UNITED STATES PATENT OFFICE.

CHARLES LUCKE, OF NEW YORK, N. Y., ASSIGNOR TO WORTHING'ION PUMP ANDMACHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIRGINIA.

INTERN AL- COMBUSTION ENGINE.

,This invention relates to improvements in internal combustion engines,and particularly to means for controlling combustion in engines of theDiesel type.

The object of the invention is to provide simple and durable means whichwill afford a more effective mixing of the fuel and air than has beenattained heretofore with a consequent more efficient combustion.

With these general objects in view, an internal combustion engineembodying the invention comprises in addition to the cylinder andpiston, a precombustion space in communication with the cylinder andcomprising the largest part or substantially all of the clearance spacebehind the piston, this precombustion space being divided into twochambers, connected with each other by a passage or passages ofrelatively restricted area, the chamber most remote from the cylinderforming what may be termed a fuel injection chamber, while the chambernearest the cylinder forms what may be termed a mixing chamber) The fuelinjection chamber receives the fuel first, and owing to the partialignition which occurs therein the mixed gases and unconsumedfuel aredriven into and well mixed in the mixing chamber, where some furthercombustion takes place,

cylinder.

The invention will now be more specifically described in connection withthe accompanying drawings and then particularly pointed out hereinafter.

In the drawings,

Fig. 1 is a diagrammatic sectional view of so much of an internalcombustion engine as is necessary to explain the invention;.and

Fig. 2 shows a modified form of nozzle device.

Referring to the drawings, A indicates the cylinder of the engine and Bthe piston. In the best embodiment of the engine, the piston approachesso close to the inner end of thecylinder on the inner dead center thatthere is substantially no clearance behind the piston within thecylinder proper.

At C and D are indicated two chambers having a throttled or restrictedcommunication with each other. In the present example the chambers areshown as separated from each other by a wall E having a circular openingin which may be secured a nozzle device such as shown, for example,.at

and finally the mixture is expelled to the F, Fig. 1, which may be ashouldered bushing arranged to fit tightly into the opening in the wallE, this bushing having a central circular passage whose intermediateportion is a short cylinder, while its end portions enlarge in eachdirection from such Intermediate portion, as will be clear from thedrawmgs.

The chamber D communicates with the cylinder through a passage d,provided with 05 a nozzle device F. which may be similar to the oneshown at F but having a discharge opening of somewhat larger area.

Any suitable means may be provided for injecting fuel into the chamberC, but in 7 the best embodiment of the invention the fuel injectingdevice G is arranged to discharge the fuel in the general direction ofthe axis of the chambers C and D.

In the best embodiment of the invention means for introducing air to thecylinder and for exhausting the burnt products of combustion. This meansmay consist of the usual inlet and outlet valves or ports controlled bythe iston (not shown).

In that em odiment of the invention where the fuel is ignited.immediately upon its entrance into the fuel injection chamber C, by theheat of compression of the air in said chamber 0, the total clearancebehind the piston must have such a ratio tothe volume swept by thepiston, that the final compression will cause the ignition. .As thetotal clearance is made up principally of the clearances in the twochambers, the respective volumes of these chambers must be properlyrelated to the stroke and diameter of the piston to produce the desiredresult. Furthermore, an additional important feature of the inventionconsists in makin the two chambers so that their diameters w1ll be lessthan the diameter of the cylinder, and in the best embodiment of theinvention the volume of the fuel injection chamber is less than that ofthe mixing chamber D. More-- over, a great advantage results in havingthe no length of the chamber in the direction of its axis so short thatthe fuel, when injected into the compressed air in the chamber C, canpassfully across and reach, under its velocity of in ection,substantially to or even through the nozzle device F.

The'operation of the best embodiment of the invention is as follows:

the chamber 0 takes place.

The cylinder receives a charge of air and this charge is compressed bythe piston into the clearance space constituted principally by the twochambers. The communication between the cylinder and the chamber D,although somewhat restricted, is still sufficient' to allow the passageof the air from the cylinder to the chamber D without much throttling,so that there is but a slight difference in pressure between thecylinder and said chamber D during and at the end of the compressionstroke. But the passage through the nozzle device F is more restrictedthan that through F, so that there will be more difference in pressurebetween the compressed air in the cylinder and that in the chamber Cduring and at the end of the compression stroke. At the proper instant,which may be in advance of or at the moment of the arrival of the pistonat its inner dead center, the injection of fuel into Owing to thesomewhat lesser pressure of the compressed air in C and the relativelyshort distance the fuel has to travel, the fuel will not require a highinjection pressure to deliver it. As soon as the fuel enters thevchamber C, ignition occurs due to the heat of compression of the air.But-owing to the size of the chamber 0 relative to the amount of fuelsupplied, there is not sufiicient air for a com plete combustion of thefuel. However, some of its burns and creates sufiicient heat andpressure to assist in va orizing some of the remaining fuel and to rivethe mixture consisting of products of combustion, vapor and particles ofunburned fuel, into the chamber D through the nozzle device F, whlch, onaccount of its construction, tends to send the mixture in suchdirections and wlth such a pressure-in excess of that in chamber D that,owing to the relatively restricted diameter of said chamber D, it canreadily reach all parts of said chamber and thus be mixed well with theair therein. Hence further combustion-takes place in this chamber D, theheat and pressure thereby generated being suflicient to assist inejectmg the mixture into the cylinder through the nozzle device F whichthoroughly distributes the burning mixture in the space behind thepiston as the latter moves forward under the pressure. I

The injection of 'fuel into chamber 0 may terminate at or before theinstant the piston reaches the inner dead center, or at somepoint'during the working stroke, as may be desired. During the time offuel injection an (wer-pressure in said chamber during the period offuel injection, whereby the mixture will be driven from the chamber Cthrough the chamber D and into the cylinder A. I

During the exhaust there will be a rush of gases from the chambers C andD into the cylinder and. out through the exhaust openings until thepressure in said chambers drops to the atmospheric pressure, the outwarddischarge from chamber (rthrough chamber D tendingto clear the latterchamber' of carbon particles, if any have been deposited therein.

On the next compression stroke any remaining products of combustion inthe two chambers and their passage ways will be compressed back intochamber C only, leaving chamber D filled with substantially pure air.Any products of combustion which may remain in chamber C are notdisadvantageous but rather a benefit as such products tend to dilute theair and make a mixture in which the fuel, when injected, burnsincompletely and relatively slowly, thereby assisting in preventing thecomplete combustion of fuel in the chamber C, which, of course, is notwanted.

The invention described is particularly suitable for Diesel oil engines,as it avoids many of the disadvantages heretofore existing in suchengines. It has been recognized heretofore thatgreat pressures werenecessary to pump the oil into the highly com pressed air, and obtainingsuch pressures consumed a considerable portion of the energy of theengine, as well as increased the complexity and weight of the machinery.

Where attempts have been made heretofore to force the oil into thecylinder by the combustionof some of the oil in a precombustionchamberwhich generated. a pressure to force the remainder of the oil into thecylinder there has existed the great difiiculty that the oil would notreach all the air in the cylinder clearance but only the centralportion, and hence an incomplete combustion occurred in the cylinder,thus causing a loss of unconsumed fuel in the exreaches every part ofthe cylinder space.

The nozzle device F,'shown in Fig. 1 is particularly satisfactory as ameans for distrlbutmg the mixture from the chamber C to all parts of thechamber D, but other '180 forms of nozzle devices may be employed. Forexample, instead of having the nozzle device provided with only oneopening, it may have a plurality of openings, the total area of all ofwhich will be such as to give the desired restricted communicationbetween the two chambers. One suitable form of such a nozzle device witha plurality of openings is illustrated at M in Fig. 2. In thisconstruction a cup-like structure is employed, having holes whose axesare approximately radial to the cup. The same nozzle may be substitutedfor the nozzle F between the chamber D and the cylinder.

What is claimed is: An internal combustion engine of the Diesel type inwhich the volume swept by the piston is so related to the clearance thatan ignition temperature is produced by c0mpression in all parts of theclearance, said engine having a cylinder, a piston, and a liquid fuelsupplying means, and also having a pre-combustion space constituting substantially all the clearance behind the piston, said space being dividedinto two pre-combustion chambers having only a restricted communicationwith each other, one chamber constituting a primary pre-combustionchamber arranged to receive fuel directly from the fuel supplying meansand by partial combustion to drive fuel to the other chamber, the latterchamber constituting a secondary pre-combustion chamber and being incontinuous restricted communication directly with the cylinder, saidsecondary precombustion chamber being arranged to receive fuel from. theprimary precombustion' CHARLES E. LUCKE.

